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my car is overheating, i have replaced the waterpump, thermostat, and flushed the coolant and its still overheating my next ideas are head gasket or radiator is clogged but i flushed it and it seemed fine...

1. Do not drive the car and do not pour cold water into an overheated engine - let it cool down for 30 minutes first before adding water.

2. Are you losing coolant?

3. Are there any leaks from hoses that you can see?

4. Is there water or too much water vapour coming out of your tailpipe? This can be tested by holding a cold surface to the tailpipe with the car running at idle....a wallet or mirror will do. Depending on where you live (and if it just rained), some water vapour is normal, but if you're getting more than normal water vapour, then yes, your HG (head gasket) or cylinder head at worst may have big problems.

This can often be corroborated by checking under your oil cap, looking into your crankcase and pulling out the dipstick to see if water has mixed with your engine oil.

5. It may be a case of simply not bleeding the radiator properly, which may be especially true since you've just flushed the radiator (btw, please recheck to see that all clips and hoses are back on tight). Bleeding has to be done 4 times to be truly effective. (With the cabin heater set to high and the blower set to #4) The first bleeding would be when coolant is added to the brim and overflowing through the bleed screw with the engine off. Then the engine is started and coolant is added once again after the car *has reached operating temperature* (have someone help you monitor this since there's a risk of overheating here). Then finally, the entire procedure has to be repeated once again when the engine is cold...preferably left overnight. This will eliminate pretty much all of the bubbles you could have had.

6. If you did not bleed your radiator in this way, please do so again. Afterwards, start the car, leave it at idle and watch the thermometer. Watch this for 30 minutes to check if everything is normal. Listen to music, have some beer and dinner, talk to someone on the phone, but do not take your eyes off the needle.

7. If there's no overheating, watch the gauge very often over the next 7 days. If there's no overheating, then you're totally out of the woods with no permanent damage to your system.

8. Check to see if your fan clutch is in good shape. Please search these forums or google to determine the best method of checking this.

9. Check your fusebox to see if anything is blown. Do you have an auxiliary cooling fan? If you do, your aux fan's fuse could have blown.

10. If you have an aux fan, it may not be working. Please check that.

11. You may have a busted radiator. Try to see if there are any leaks but many leaks only become visible at high pressure so it may be difficult to tell. But look at every joint of the radiator closely and under very good lighting, you may spot something. If you have any small leaks, it can be fixed with high temperature silicone window seal...I've done this on my car and its held up without problems for the past 3 months.

12. If you've not changed your radiator tank cap and bleed screw recently, please do so immediately. These two items could be sources of premature coolant loss and they are really cheap to replace.

13. There is a possibility that the prior overheating events has caused permanent damage to either your HG or your cylinder head. If so, this damage will be there even if you find and fix the original problem. You need to monitor your car carefully for some weeks after you find the original problem.

14. If you feel you've found the problem, please do #6 and #7 listed above to check.

15. Please put 3-4 gallons of water in your trunk right away. A can of very cheap coolant from the gas station wouldn't hurt either. This needs to be there for the next few weeks as a precautionary rescue kit. It can be discarded after you've determined that everything is cool , permanently.

16. Good visual observation and a clear, calm mind are the keys to finding and fixing this and pretty much any other non-obvious problems with our E34.

i have been driving it at the 3/4 mark since july thinking it was normal, it over heated 3 times after but bleeding the system and adding coolant fixed it.(to the 3/4 mark)
i have never seen it sit at 1/2 way. after sitting for weeks it stayed at the tip of the blue..

i was loosing coolant before i replaced the thermostat gasket.

and its constanly blowing out white smoke, but my oil looks fine, my dad doesnt think its the HG

the aux cooling fan doesnt work but i dont use ac, and i hotwired it to make it work and it didnt make a diff.

You may have screwed your cylinder head. What was it made of, aluminium alloy or cast iron? Should be the former. You may have screwed your cylinder head by driving at 3/4 for so long.

White smoke ! .....is this water vapour? Do the checks for water vapour i mentioned asap and post your results. Doesn't look good but if you don't have water in your oil, it might not be that bad. Then again, you are overheating....so yes it really doesn't look good at all.

Do you have a compression testing gauge? If so, please, look up the correct compression readings for your car by consulting the bentley manual for e34s, downloadable from these forums if you search for it. Do the compression test on all of your cylinders. They should be very close to the correct compression readings for your car, and there should be not more than a 5% deviation between cylinders. If you have a cracked head, this is one sure way to find it. Goto youtube for numerous videos on how to conduct this test (if you don't already know). Another useful indirect way would be to use a vacuum pressure gauge and observe its readings.

well it only smokes when its sitting in idle, and it faded away after i drove it around, it got little above 1/2 parked and bled it little more, gonna add coolant tomorrow morning. me and my dad were gonna do a cooling pressure test i have a slight leak in the little output on the top of the radiator and then replace the coolant tank cap. hopefully that helps. i cant bring myself to put too much money into it i bought it for 4k and that was too much.

Well if the smoke goes away while driving...still could be anything. But from the rest of your description, it sounds like your cooling system needs to be rexamined, and you may need to patch up or replace that radiator.

Bleed the radiator again tomorrow morning. Please follow my advise on the bleeding...the first with the engine off, fill to brim, let coolant overflow from the bleed screw, stop when the bubbles run out, repeat the whole procedure after starting the car and it reaches operating temperature. And yes, a pressure test on your radiator is an excellent idea, apologies forgot to mention that earlier. At some point, do carry out a compression test on your engine to rule out problems there too.

okk i am back, replaced the headgasket set, fixed the radiator leak with jb weld and sealed it up tight, new expansion tank cap and oil cap and bleed cap. bled it and now air is coming out just coolant.. but its still not running at the 1/2 mark it still heats up to potentialy overheat..

You may have screwed your cylinder head. What was it made of, aluminium alloy or cast iron? Should be the former. You may have screwed your cylinder head by driving at 3/4 for so long.

White smoke ! .....is this water vapour? Do the checks for water vapour i mentioned asap and post your results. Doesn't look good but if you don't have water in your oil, it might not be that bad. Then again, you are overheating....so yes it really doesn't look good at all.

Do you have a compression testing gauge? If so, please, look up the correct compression readings for your car by consulting the bentley manual for e34s, downloadable from these forums if you search for it. Do the compression test on all of your cylinders. They should be very close to the correct compression readings for your car, and there should be not more than a 5% deviation between cylinders. If you have a cracked head, this is one sure way to find it. Goto youtube for numerous videos on how to conduct this test (if you don't already know). Another useful indirect way would be to use a vacuum pressure gauge and observe its readings.

Get a new radiator. my car was doing the same thing running at 3/4 mark after i replaced my thermostat, water pump, bleeder screw and coolant cap. then i tossed a new radiator in and cools just fine now. I'm guessing your car has over 100,000 miles on so it's about time for that anyways.

Please do not drive the car until you've solved this problem. Only run the engine at idle for testing and repair purposes. Sorry but its bad. Some questions for you:

1. Is there still any smoke coming out of your tailpipe? Can you check if its steam?
2. Is there any water in your oil?
3. When you changed your head gasket, did you do a pressure test on your cylinder head? Did you change the HG yourself or get a mechanic to do it?
4. Are you still losing coolant?
5. Open your radiator's cap, fill up water till the top and run your engine at idle. Do you see tiny bubbles coming through the expansion tank? If you do, its combustion gases escaping into the cooling system through a crack in the cylinder head.
6. Do you know how to do a compression test? Do you have a compression testing gauage? Its real cheap on ebay or the shops, get one right away and conduct a compression test and post the rests here for each chamber. Check on youtube for excellent how-to videos on how to do compression tests on your engine. I mentioned that you should do this earlier. In general, when it comes to your car, do all the easier/cheaper stuff first and the harder/more expensive stuff last.
7. Post your compression test's results here for each chamber. If one or more is significantly out, then that's probably a sign of a cracked head, especially if its accompanied by numerous little bubbles in the expansion tank's water.
8. As most cracks in cylinder heads are not visible to the naked eye, the only way to confirm that its actually there is via a pressure test.
9. It is usually not advisable to attempt to repair/weld/etc a cracked head and reuse it.
10. There are some coolant additive products out there which claim to plug up leaks in cracked heads. They probably don't work, but well you can always give it a try.

In my earlier posts, I did not mention that you should do a pressure test on your cylinder head if you change the HG. It slipped my mind, and it wasn't clear that you were going to change it in the first place. However, if you changed your HG with a professional workshop, and if they did not advise you that its a good idea to have the cylinder head pressure tested due to the persistent overheating, and if you find that your cylinder head is indeed cracked, then right to sue them for the new repair or have them pay for it less the cost of the cylinder head, but with compensation for a rental car for the additional downtime. This is something the professionals should know and do automatically.

You probably have a cracked head. Start checking around for good used cylinder heads for your car. Go for the stuff that's cleaned, pressure tested to have no leaks and has a warranty. Purchase from reputable companies. Do your research first but don't pay for anything yet until you've confirmed that this is the problem on your car. Spend as little as possible on this but only buy from reliable companies. If you find a spectacular deal on a cylinder head but the origin is suspect, have the head sent somewhere for a pressure test after you receive it to confirm that its in good condition.

If you need to change your head, you need to do a top overhaul on your car. This is very time consuming. If you have a cracked head and you change it, your overheating problem will be solved permanently. If you do a top overhaul on your car, its performance will be significantly improved from before. If you do a top overhaul on your car or change the head gasket, have the piston tops cleaned of all the accumulated carbon. Yes you've spent too much on the purchase price for your car. So, if you have a cylinder head problem, consider the costs involved. It may be cheaper to purchase another 535 instead. It may be cheaper to purchase a used m30 (or m60 ) ) motor and plonk it in instead of doing a top overhaul, depending on your circumstances.

Please answer every single question I've listed here in the order in which it has been presented. Easier for me to follow

Get a new radiator. my car was doing the same thing running at 3/4 mark after i replaced my thermostat, water pump, bleeder screw and coolant cap. then i tossed a new radiator in and cools just fine now. I'm guessing your car has over 100,000 miles on so it's about time for that anyways.

If your compression tests are normal, then before you take Calaurion's advice above on getting a new radiator thank the heavens for being so kind.

And, oh, btw, please check if your clutch fan is working properly. Turn it with your fingers with the engine off, it should be difficult to push. If it turns pretty easily, then that needs to be replaced, and that could be your problem as well. Good luck.

Lucky's motor is an M30. I'm not sure what its made of. If its made of cast iron, lucky is indeed a lucky dude....those things are bulletproof, you've probably just got a coolant system leak somewhere.

Lucky's motor is an M30. I'm not sure what its made of. If its made of cast iron, lucky is indeed a lucky dude....those things are bulletproof, you've probably just got a coolant system leak somewhere.

did you have head checked for warpage? did you replace head bolts when you replaced gasket? did you torque and angle head bolts in proper sequence when you reinstalled?. are you elevating front of car when you are bleeding. do you have the heater on in the full heat position when you are bleeding? any coolant in oil or oil in coolant, white smoke? need alot more info in order to help diangnose. dont just start replacing expensive components until you have diagnosed. all suggestions can cause car to run hot but the bill gets stiff things are just replaced with out knowing they have failed.fwiw.

sounds like blocked radiator. when you changed the water pump was it the original with plastic blades. it might have disintegrated and gotten lodged in the radiator. take out the radiator and backflush from bottom with the radiator upside down and see if you can dislodge the blockage.

i just changed my head gasket on my car and also did a flush and still the car was over heating 3/4 so i decided to remove some of the hoses and blow into them there was blockage by the heater valve took me 10 min to clear the blockage after removing the top radiator hose and putting a garden hose full blast had all this white stuff come out waited till it came out clear reattached the hoses and the motor ran fine no more 3/4 try that might have a blockage

It happened to me the other day, 535I 2008 with 71K, Now I asked my dealer in the my area on how much will it cost to get it replaced, it will be about $1,400-1,800. I'm thinking replacing it myself. The parts will cost me from Turner Motorsports about $600 with Thermostat. Now, does anybody here have an idea a step by step on how? Any suggestion on where to get the parts from reputable web store?

just my .02
Was all of this occuring prior to you doing anything to the car?
I ask for if it wasn't, then you're going to have to back track what you done.
which sucks.

However If you performed all the necessary or better said common issues with your m30b35.
Then you should begin to look at your electricals namely your sensors for you cooling system.
People tend to forget about them and change out everything else.
There are four:

The blue and black sensors deal with your temp gauge.
One goes before the other. Sorry I forgot which kicks the bucket first.
To be safe replace both. You can buy them new or hit a junkyard for them.
The one on the radiator does as well but that's more of a aux fan control.

The one in your expansion tank deals with your coolant level.
Not really related unless it's not reading on the dash and you open the expansion tank only to see no coolant or it gushing out.
Another junkyard gem to pick up. If you get one from a junkyard get the connector too. That socket likes to crumble with age.

Your aux fan probably needs a resistor bypass or again a new sensor.
If the end of the sensor can move. Or the male connection is f'd up (another that crumbles with age).
Probably time for a new one.
The resistor bypass is a common issue. (the small black wired brick on the side of your aux fan frame) just eliminate it by splicing around it.
Doesn't hurt the car.

What type temp grad is you're thermostat?
There are 2. I use the higher temp thermostat

Have you checked all your coolant hoses? Were there any pin hole leaks?
These type of leaks no matter how minor can throw the cooling system off.
Look for white hazy stains or wet marks along the radiator, thermostat, lower part of the engine block, on the or around expansion tank.
Especially check your floor board behind the passenger seat. The heat core drain falls back there. If it's damp. You found your leak.

Check your vaccum hoses. Just throwin that one out there.

Y U JB Weld your radiator?!?
Hit the junkyard and pick one up for a little more than what you paid for JBweld.

Like robert stated it could be many different factors.
Being we're talking about a M30. 9/10 the issues are not that bad.
Just a factor of hunting them down and knocking them off one by one.

It can be time consuming. But nothing a novice with a bentley and minor tools can't pull off.

Also you have to remember these cars are not spring chickens.
Unless you pick up a cherry e34. You're going to have to pull out the debit or credit card for a few things.

It happened to me the other day, 535I 2008 with 71K, Now I asked my dealer in the my area on how much will it cost to get it replaced, it will be about $1,400-1,800. I'm thinking replacing it myself. The parts will cost me from Turner Motorsports about $600 with Thermostat. Now, does anybody here have an idea a step by step on how? Any suggestion on where to get the parts from reputable web store?